Mass. Gen. Laws ch. 125, § 3: Officers and employees of institutions; appointment; duties of correction officer or correctional program officer

Section 3. All other officers and all employees in the said institutions shall be appointed by the commissioner, and, except as otherwise provided in chapter thirty and thirty-one, shall hold office during his pleasure. The duties of a correction officer or correctional program officer shall include the duty to transport inmates outside of a correctional facility and to prevent their escape, and no special state police officer appointment under section 127 of chapter 127 shall be necessary for such purposes.